1FGU

SSDNA-BINDING DOMAIN OF THE LARGE SUBUNIT OF REPLICATION PROTEIN A

Summary for 1FGU

• Entry DOI: 10.2210/pdb1fgu/pdb
• Related: 1jmc
• Descriptor: REPLICATION PROTEIN A 70 KDA DNA-BINDING SUBUNIT (2 entities in total)
• Functional Keywords: ob-fold, ssdna-binding protein, replication
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 2
• Total formula weight: 56219.28

Authors

Bochkareva, E.,Belegu, V.,Korolev, S.,Bochkarev, A. (deposition date: 2000-07-28, release date: 2001-02-07, Last modification date: 2024-02-07)

Primary citation

Bochkareva, E.,Belegu, V.,Korolev, S.,Bochkarev, A.
Structure of the major single-stranded DNA-binding domain of replication protein A suggests a dynamic mechanism for DNA binding.
EMBO J., 20:612-618, 2001

PubMed Abstract: Although structures of single-stranded (ss)DNA-binding proteins (SSBs) have been reported with and without ssDNA, the mechanism of ssDNA binding in eukarya remains speculative. Here we report a 2.5 Angstroms structure of the ssDNA-binding domain of human replication protein A (RPA) (eukaryotic SSB), for which we previously reported a structure in complex with ssDNA. A comparison of free and bound forms of RPA revealed that ssDNA binding is associated with a major reorientation between, and significant conformational changes within, the structural modules--OB-folds--which comprise the DNA-binding domain. Two OB-folds, whose tandem orientation was stabilized by the presence of DNA, adopted multiple orientations in its absence. Within the OB-folds, extended loops implicated in DNA binding significantly changed conformation in the absence of DNA. Analysis of intermolecular contacts suggested the possibility that other RPA molecules and/or other proteins could compete with DNA for the same binding site. Using this mechanism, protein-protein interactions can regulate, and/or be regulated by DNA binding. Combined with available biochemical data, this structure also suggested a dynamic model for the DNA-binding mechanism.

PubMed: 11157767
DOI: 10.1093/emboj/20.3.612

Experimental method

X-RAY DIFFRACTION (2.5 Å)